As distributors of MPEG-2 transport streams have become more successful at reducing the video bit rate, the fraction of total encoder bit rate used for encoding the audio has increased. Encoded audio is utilized in many applications, including, multiplexed broadcast signals, such as Digital Video Broadcasting (DVB) signals, where several video and audio streams share a constant bit rate of a transmitter or transponder. Encoded audio is also utilized where storage and/or transmission of audio signals, for example via a modem, represents a burden or cost, and minimization of that cost is desired.
Therefore, there is a need in the art for a method and apparatus to reduce the audio bit rate, with minimal or no degradation in quality.